A few weeks ago came the news that VMware, already well established as the poster child of enterprise server virtualisation, was extending its reach down into the small and medium-sized business world. There is a sub-text to this announcement, however, that opens up the world of Software as a Service (SaaS), not only to the small business user but also to their enterprise equivalent – the small department. Indeed, it has the potential to open up SaaS to major enterprises in the same way they grew to love Linux – by departmental stealth.

SaaS is already getting to be of interest to smaller businesses – as witnessed by the success of offerings like NetSuite, Salesforce.com and many others – but there is still a long way to go for it to have claimed to fulfil its obvious potential. One reason, I suspect, is because there are a large number of potential users with established, legacy applications wondering how they get from where they are to the brave new SaaS world.

`Legacy’ in this context actually means that panoply of applications and office productivity tools that run on Windows. These are not only the staple diet of the small business, either: they are also the bedrock on which most large enterprise departments are built, which means they have the same scope as small businesses to consider SaaS as future delivery option.

As one of the potential stumbling blocks for both parties is likely to be the perceived problem of how they get from the `here’ of on-site applications to the `there’ of hosted, managed SaaS delivery, the ability to re-use existing legacy applications could be just the bridging mechanism they require. With VMware claiming that just about anything that can be run on any x86 architecture can be considered as potentially viable in a small SaaS environment, then much of that fear of doing something new can be removed.

As one of its touchstone little tests, VMware often uses an ancient PC game from the Windows 3.x era, and this has been found to run as an effective deliverable in a multi-tenanted SaaS environment.

Yes, there are likely to be some issues here, not least with seriously non-trivial details such as licence rights on legacy applications in a new environment. But the ability to use VMware to create a small, multi-tenanted SaaS environment re-using existing applications has the potential to provide a very useful start point for not only the small business, but also the enterprise department; and it has often been the case that those departments have been the proving grounds on which significant new developments have been tested.

At a time when much of the technology of the infrastructure is, in effect, a `done deal’ and well on its way to becoming additions in the commodity product roster that IT vendors are generating, it would seem sensible to suppose that embedding at least some of the smaller commodities into some of the larger ones would make sense. That is, one assumes, the thinking behind the announcement by VMware of its new, embeddable, ESX 3i virtualisation hypervisor. However, while it looks damned good on paper, there may be some risks attached for any user going down that route.

On paper the idea is indeed pretty damned good. There is a great deal of sense in integrating as much as possible of the slow-changing technologies into the core systems of the infrastructure. This is exactly what Intel has done, for example, with many functions that were external to the `CPU’ but are now an integral part of the `processor’. Graphics processing capabilities is just one obvious case in point. Indeed, the `CPU’ is, in real estate terms, now almost a side issue in most processor chips, given what else is integrated into the silicon.

So the notion of VMware burning the ESX code into a memory chip for incorporation into a server motherboard would seem to be just one more step along that road. In time it might well prove to be the case, but that phrase, `in time’, is potentially quite important here. Virtualisation may have been the buzzword de jour for the last couple of years but the issues surrounding the technologies that implement it, the APIs that integrate it - or even the concepts surrounding what different vendors mean by virtualisation and what different users think they expect to see from it – are still too numerous and nebulous to contemplate being set in the type of technical concrete needed for an embeddable technology.

For a start, VMware is suggesting that the ESX hypervisor is going to make the implementation of virtualised systems a great deal easier because most of the technology is embedded – sysadmins will be relieved of much of the burden of setting up a virtualised environment, which on the face of it sounds good. But this has serious potential to hark back to the bad old days (OK, the current days for many users) where the IT environment, maybe even the whole business, has to be tailored round what the technology can offer, not necessarily what the business actually requires.

Also, ESX will be shipped with VMware’s existing management software. But in many infrastructures it is virtualisation at the systems level rather then chip level that can offer significant performance and flexibility advantages, and here the systems management software that matters is IBM’s Tivoli, HP’s OpenView, BMC’s Patrol and the rest.

The one advantage for users is that it looks like most of the commodity (x86) server vendors are going to bundle ESX, and some will probably also bundle ZenSource as well. They’ll probably bundle them all as they appear, which means users can ignore them all without fear of showing favour. At best, it means they can dedicate a couple of server boxes to a sandbox to find out just how useful this all might be in the real world. It may even be great.